/*!
 * mustache.js - Logic-less {{mustache}} templates with JavaScript
 * http://github.com/janl/mustache.js
 */

/*global define: false*/

(function (root, factory) {
    if (typeof exports === "object" && exports) {
        module.exports = factory; // CommonJS
    } else if (typeof define === "function" && define.amd) {
        define(factory); // AMD
    } else {
        root.Mustache = factory; // <script>
    }
}(this, (function () {

    var exports = {};

    exports.name = "mustache.js";
    exports.version = "0.7.2";
    exports.tags = ["{{", "}}"];

    exports.Scanner = Scanner;
    exports.Context = Context;
    exports.Writer = Writer;

    var whiteRe = /\s*/;
    var spaceRe = /\s+/;
    var nonSpaceRe = /\S/;
    var eqRe = /\s*=/;
    var curlyRe = /\s*\}/;
    var tagRe = /#|\^|\/|>|\{|&|=|!/;

    // Workaround for https://issues.apache.org/jira/browse/COUCHDB-577
    // See https://github.com/janl/mustache.js/issues/189
    function testRe(re, string) {
        return RegExp.prototype.test.call(re, string);
    }

    function isWhitespace(string) {
        return !testRe(nonSpaceRe, string);
    }

    var isArray = Array.isArray || function (obj) {
        return Object.prototype.toString.call(obj) === "[object Array]";
    };

    function escapeRe(string) {
        return string.replace(/[\-\[\]{}()*+?.,\\\^$|#\s]/g, "\\$&");
    }

    var entityMap = {
        "&": "&amp;",
        "<": "&lt;",
        ">": "&gt;",
        '"': '&quot;',
        "'": '&#39;',
        "/": '&#x2F;'
    };

    function escapeHtml(string) {
        return String(string).replace(/[&<>"'\/]/g, function (s) {
            return entityMap[s];
        });
    }

    // Export the escaping function so that the user may override it.
    // See https://github.com/janl/mustache.js/issues/244
    exports.escape = escapeHtml;

    function Scanner(string) {
        this.string = string;
        this.tail = string;
        this.pos = 0;
    }

    /**
     * Returns `true` if the tail is empty (end of string).
     */
    Scanner.prototype.eos = function () {
        return this.tail === "";
    };

    /**
     * Tries to match the given regular expression at the current position.
     * Returns the matched text if it can match, the empty string otherwise.
     */
    Scanner.prototype.scan = function (re) {
        var match = this.tail.match(re);

        if (match && match.index === 0) {
            this.tail = this.tail.substring(match[0].length);
            this.pos += match[0].length;
            return match[0];
        }

        return "";
    };

    /**
     * Skips all text until the given regular expression can be matched. Returns
     * the skipped string, which is the entire tail if no match can be made.
     */
    Scanner.prototype.scanUntil = function (re) {
        var match, pos = this.tail.search(re);

        switch (pos) {
            case -1:
                match = this.tail;
                this.pos += this.tail.length;
                this.tail = "";
                break;
            case 0:
                match = "";
                break;
            default:
                match = this.tail.substring(0, pos);
                this.tail = this.tail.substring(pos);
                this.pos += pos;
        }

        return match;
    };

    function Context(view, parent) {
        this.view = view;
        this.parent = parent;
        this.clearCache();
    }

    Context.make = function (view) {
        return (view instanceof Context) ? view : new Context(view);
    };

    Context.prototype.clearCache = function () {
        this._cache = {};
    };

    Context.prototype.push = function (view) {
        return new Context(view, this);
    };

    Context.prototype.lookup = function (name) {
        var value = this._cache[name];

        if (!value) {
            if (name === ".") {
                value = this.view;
            } else {
                var context = this;

                while (context) {
                    if (name.indexOf(".") > 0) {
                        var names = name.split("."), i = 0;

                        value = context.view;

                        while (value && i < names.length) {
                            value = value[names[i++]];
                        }
                    } else {
                        value = context.view[name];
                    }

                    if (value != null) {
                        break;
                    }

                    context = context.parent;
                }
            }

            this._cache[name] = value;
        }

        if (typeof value === "function") {
            value = value.call(this.view);
        }

        return value;
    };

    function Writer() {
        this.clearCache();
    }

    Writer.prototype.clearCache = function () {
        this._cache = {};
        this._partialCache = {};
    };

    Writer.prototype.compile = function (template, tags) {
        var fn = this._cache[template];

        if (!fn) {
            var tokens = exports.parse(template, tags);
            fn = this._cache[template] = this.compileTokens(tokens, template);
        }

        return fn;
    };

    Writer.prototype.compilePartial = function (name, template, tags) {
        var fn = this.compile(template, tags);
        this._partialCache[name] = fn;
        return fn;
    };

    Writer.prototype.compileTokens = function (tokens, template) {
        var fn = compileTokens(tokens);
        var self = this;

        return function (view, partials) {
            if (partials) {
                if (typeof partials === "function") {
                    self._loadPartial = partials;
                } else {
                    for (var name in partials) {
                        self.compilePartial(name, partials[name]);
                    }
                }
            }

            return fn(self, Context.make(view), template);
        };
    };

    Writer.prototype.render = function (template, view, partials) {
        return this.compile(template)(view, partials);
    };

    Writer.prototype._section = function (name, context, text, callback) {
        var value = context.lookup(name);

        switch (typeof value) {
            case "object":
                if (isArray(value)) {
                    var buffer = "";

                    for (var i = 0, len = value.length; i < len; ++i) {
                        buffer += callback(this, context.push(value[i]));
                    }

                    return buffer;
                }

                return value ? callback(this, context.push(value)) : "";
            case "function":
                var self = this;
                var scopedRender = function (template) {
                    return self.render(template, context);
                };

                var result = value.call(context.view, text, scopedRender);
                return result != null ? result : "";
            default:
                if (value) {
                    return callback(this, context);
                }
        }

        return "";
    };

    Writer.prototype._inverted = function (name, context, callback) {
        var value = context.lookup(name);

        // Use JavaScript's definition of falsy. Include empty arrays.
        // See https://github.com/janl/mustache.js/issues/186
        if (!value || (isArray(value) && value.length === 0)) {
            return callback(this, context);
        }

        return "";
    };

    Writer.prototype._partial = function (name, context) {
        if (!(name in this._partialCache) && this._loadPartial) {
            this.compilePartial(name, this._loadPartial(name));
        }

        var fn = this._partialCache[name];

        return fn ? fn(context) : "";
    };

    Writer.prototype._name = function (name, context) {
        var value = context.lookup(name);

        if (typeof value === "function") {
            value = value.call(context.view);
        }

        return (value == null) ? "" : String(value);
    };

    Writer.prototype._escaped = function (name, context) {
        return exports.escape(this._name(name, context));
    };

    /**
     * Low-level function that compiles the given `tokens` into a function
     * that accepts three arguments: a Writer, a Context, and the template.
     */
    function compileTokens(tokens) {
        var subRenders = {};

        function subRender(i, tokens, template) {
            if (!subRenders[i]) {
                var fn = compileTokens(tokens);
                subRenders[i] = function (writer, context) {
                    return fn(writer, context, template);
                };
            }

            return subRenders[i];
        }

        return function (writer, context, template) {
            var buffer = "";
            var token, sectionText;

            for (var i = 0, len = tokens.length; i < len; ++i) {
                token = tokens[i];

                switch (token[0]) {
                    case "#":
                        sectionText = template.slice(token[3], token[5]);
                        buffer += writer._section(token[1], context, sectionText, subRender(i, token[4], template));
                        break;
                    case "^":
                        buffer += writer._inverted(token[1], context, subRender(i, token[4], template));
                        break;
                    case ">":
                        buffer += writer._partial(token[1], context);
                        break;
                    case "&":
                        buffer += writer._name(token[1], context);
                        break;
                    case "name":
                        buffer += writer._escaped(token[1], context);
                        break;
                    case "text":
                        buffer += token[1];
                        break;
                }
            }

            return buffer;
        };
    }

    /**
     * Forms the given array of `tokens` into a nested tree structure where
     * tokens that represent a section have two additional items: 1) an array of
     * all tokens that appear in that section and 2) the index in the original
     * template that represents the end of that section.
     */
    function nestTokens(tokens) {
        var tree = [];
        var collector = tree;
        var sections = [];

        var token;
        for (var i = 0, len = tokens.length; i < len; ++i) {
            token = tokens[i];
            switch (token[0]) {
                case '#':
                case '^':
                    sections.push(token);
                    collector.push(token);
                    collector = token[4] = [];
                    break;
                case '/':
                    var section = sections.pop();
                    section[5] = token[2];
                    collector = sections.length > 0 ? sections[sections.length - 1][4] : tree;
                    break;
                default:
                    collector.push(token);
            }
        }

        return tree;
    }

    /**
     * Combines the values of consecutive text tokens in the given `tokens` array
     * to a single token.
     */
    function squashTokens(tokens) {
        var squashedTokens = [];

        var token, lastToken;
        for (var i = 0, len = tokens.length; i < len; ++i) {
            token = tokens[i];
            if (token[0] === 'text' && lastToken && lastToken[0] === 'text') {
                lastToken[1] += token[1];
                lastToken[3] = token[3];
            } else {
                lastToken = token;
                squashedTokens.push(token);
            }
        }

        return squashedTokens;
    }

    function escapeTags(tags) {
        return [
            new RegExp(escapeRe(tags[0]) + "\\s*"),
            new RegExp("\\s*" + escapeRe(tags[1]))
        ];
    }

    /**
     * Breaks up the given `template` string into a tree of token objects. If
     * `tags` is given here it must be an array with two string values: the
     * opening and closing tags used in the template (e.g. ["<%", "%>"]). Of
     * course, the default is to use mustaches (i.e. Mustache.tags).
     */
    exports.parse = function (template, tags) {
        template = template || '';
        tags = tags || exports.tags;

        if (typeof tags === 'string') tags = tags.split(spaceRe);
        if (tags.length !== 2) {
            throw new Error('Invalid tags: ' + tags.join(', '));
        }

        var tagRes = escapeTags(tags);
        var scanner = new Scanner(template);

        var sections = [];     // Stack to hold section tokens
        var tokens = [];       // Buffer to hold the tokens
        var spaces = [];       // Indices of whitespace tokens on the current line
        var hasTag = false;    // Is there a {{tag}} on the current line?
        var nonSpace = false;  // Is there a non-space char on the current line?

        // Strips all whitespace tokens array for the current line
        // if there was a {{#tag}} on it and otherwise only space.
        function stripSpace() {
            if (hasTag && !nonSpace) {
                while (spaces.length) {
                    tokens.splice(spaces.pop(), 1);
                }
            } else {
                spaces = [];
            }

            hasTag = false;
            nonSpace = false;
        }

        var start, type, value, chr;
        while (!scanner.eos()) {
            start = scanner.pos;
            value = scanner.scanUntil(tagRes[0]);

            if (value) {
                for (var i = 0, len = value.length; i < len; ++i) {
                    chr = value.charAt(i);

                    if (isWhitespace(chr)) {
                        spaces.push(tokens.length);
                    } else {
                        nonSpace = true;
                    }

                    tokens.push(["text", chr, start, start + 1]);
                    start += 1;

                    if (chr === "\n") {
                        stripSpace(); // Check for whitespace on the current line.
                    }
                }
            }

            start = scanner.pos;

            // Match the opening tag.
            if (!scanner.scan(tagRes[0])) {
                break;
            }

            hasTag = true;
            type = scanner.scan(tagRe) || "name";

            // Skip any whitespace between tag and value.
            scanner.scan(whiteRe);

            // Extract the tag value.
            if (type === "=") {
                value = scanner.scanUntil(eqRe);
                scanner.scan(eqRe);
                scanner.scanUntil(tagRes[1]);
            } else if (type === "{") {
                var closeRe = new RegExp("\\s*" + escapeRe("}" + tags[1]));
                value = scanner.scanUntil(closeRe);
                scanner.scan(curlyRe);
                scanner.scanUntil(tagRes[1]);
                type = "&";
            } else {
                value = scanner.scanUntil(tagRes[1]);
            }

            // Match the closing tag.
            if (!scanner.scan(tagRes[1])) {
                throw new Error('Unclosed tag at ' + scanner.pos);
            }

            // Check section nesting.
            if (type === '/') {
                if (sections.length === 0) {
                    throw new Error('Unopened section "' + value + '" at ' + start);
                }

                var section = sections.pop();

                if (section[1] !== value) {
                    throw new Error('Unclosed section "' + section[1] + '" at ' + start);
                }
            }

            var token = [type, value, start, scanner.pos];
            tokens.push(token);

            if (type === '#' || type === '^') {
                sections.push(token);
            } else if (type === "name" || type === "{" || type === "&") {
                nonSpace = true;
            } else if (type === "=") {
                // Set the tags for the next time around.
                tags = value.split(spaceRe);

                if (tags.length !== 2) {
                    throw new Error('Invalid tags at ' + start + ': ' + tags.join(', '));
                }

                tagRes = escapeTags(tags);
            }
        }

        // Make sure there are no open sections when we're done.
        var section = sections.pop();
        if (section) {
            throw new Error('Unclosed section "' + section[1] + '" at ' + scanner.pos);
        }

        return nestTokens(squashTokens(tokens));
    };

    // The high-level clearCache, compile, compilePartial, and render functions
    // use this default writer.
    var _writer = new Writer();

    /**
     * Clears all cached templates and partials in the default writer.
     */
    exports.clearCache = function () {
        return _writer.clearCache();
    };

    /**
     * Compiles the given `template` to a reusable function using the default
     * writer.
     */
    exports.compile = function (template, tags) {
        return _writer.compile(template, tags);
    };

    /**
     * Compiles the partial with the given `name` and `template` to a reusable
     * function using the default writer.
     */
    exports.compilePartial = function (name, template, tags) {
        return _writer.compilePartial(name, template, tags);
    };

    /**
     * Compiles the given array of tokens (the output of a parse) to a reusable
     * function using the default writer.
     */
    exports.compileTokens = function (tokens, template) {
        return _writer.compileTokens(tokens, template);
    };

    /**
     * Renders the `template` with the given `view` and `partials` using the
     * default writer.
     */
    exports.render = function (template, view, partials) {
        return _writer.render(template, view, partials);
    };

    // This is here for backwards compatibility with 0.4.x.
    exports.to_html = function (template, view, partials, send) {
        var result = exports.render(template, view, partials);

        if (typeof send === "function") {
            send(result);
        } else {
            return result;
        }
    };

    return exports;

}())));